In 1966, Daimler still occupied a distinctly British luxury niche, blending formal saloon character with the marque’s traditional emphasis on refinement while also carrying forward the sporting SP 250. That makes 1966 Daimler an especially interesting year from a tire standpoint, because the range was not built around one universal size. Three models use five different tire sizes overall, with a mix of 15-inch and 16-inch fitments and a clear split between bias-ply and radial choices depending on the model. Before choosing a tire for 1966 Daimler, the first step is to confirm whether you have a 2.5 Litre, 4.5 Litre, or SP 250, then match the correct size and construction style.
Which Tire Size Is Right for Your 1966 Daimler
Five tire sizes are used across 1966 Daimler models, and they vary by model rather than carrying across the full range. The real decision starts with confirming the correct model and rim diameter first, then choosing between bias-ply and radial construction where both were used on the same model family. Understanding that distinction before choosing a product saves time and helps ensure the right match.
Year(s): 1966|Fit(s): 2.5 Litre|Construction: Radial|Rim: 15 in
185R15 is a radial metric size with a nominal section width of 185 millimeters and a 15-inch rim diameter, with the unstated profile conventionally treated as an 80-series radial. This size is specific to the 1966 Daimler 2.5 Litre and is available from Coker Classic and Michelin in redline, narrow whitewall, and blackwall styles; all examples here are tubeless, and speed ratings vary by product, including H up to 130 mph and V up to 149 mph. Buyers who want a more modern radial driving feel in a 2.5 Litre will usually focus on this size rather than a bias-ply alternative.
Year(s): 1966|Fit(s): 2.5 Litre|Construction: Bias Ply|Rim: 15 in
640-15 is a numeric bias-ply size in which 6.40 denotes nominal section width and 15 denotes the rim diameter in inches. This size is specific to the 1966 Daimler 2.5 Litre and is available from BFGoodrich and Firestone with wide whitewall and narrow whitewall treatments; load-capacity figures on current offerings include 970 pounds at 32 psi and 1190 pounds at 32 psi. Buyers restoring a 2.5 Litre to a more period-authentic look will usually gravitate toward this size because it preserves traditional bias-ply character and sidewall styling.
Year(s): 1966|Fit(s): 4.5 Litre|Construction: Bias Ply|Rim: 16 in
700-16 is a numeric bias-ply size with a nominal 7.00-inch section width and a 16-inch rim diameter. This size is exclusive to the 1966 Daimler 4.5 Litre and is available from Lester, Avon, BFGoodrich, and Firestone in blackwall and wide whitewall form; speed-rating information appears on some products, including L up to 75 mph, and load figures reach 1800 pounds at 36 psi, 1874 pounds, and 1900 pounds at 36 psi depending on the tire. Buyers choosing for a 4.5 Litre need to stay with this 16-inch fitment and then decide which sidewall look best suits the car’s intended presentation.
Year(s): 1966|Fit(s): SP 250|Construction: Radial|Rim: 15 in
165R15 is a radial metric size with a nominal section width of 165 millimeters and a 15-inch rim diameter, with the profile conventionally understood as an 80-series radial when no aspect ratio is stated. This size is specific to the 1966 Daimler SP 250 and is available from Coker Classic, American Classic, Firestone, and BFGoodrich in wide whitewall, narrow whitewall, and blackwall styles; load figures run from 1168 pounds at 35 psi to 1170 pounds at 36 psi. Drivers who want radial construction on an SP 250 often start here, especially when road use matters as much as appearance.
Year(s): 1966|Fit(s): SP 250|Construction: Bias Ply|Rim: 15 in
590-15 is a numeric bias-ply size in which 5.90 refers to nominal section width and 15 identifies the rim diameter in inches. This size is specific to the 1966 Daimler SP 250 and is available from BFGoodrich and Avon in blackwall and wide whitewall form; speed-rating information varies by product, with H-rated examples carrying a 130 mph ceiling, and load figures include 1018 pounds and 1050 pounds at 32 psi. Owners aiming for a more period-style SP 250 presentation will often prefer this size over the radial alternative.
Three Daimler models are covered for 1966, and tire size varies by model rather than carrying across the whole make. That means year and make alone are not enough here: a 2.5 Litre, 4.5 Litre, and SP 250 each point to a different fitment path, with the saloons and sports car also splitting between bias-ply and radial choices in different ways. Select your model below to narrow the correct size and see model-specific tire options.
1966 Daimler 2.5 Litre
The 2.5 Litre was Daimler’s compact sporting saloon, closely associated with the V8-powered Jaguar-derived body style that gave the marque a more agile and contemporary presence in the mid-1960s. Its tires mount on 15-inch wheels, and it is one of the few 1966 Daimler models here with a direct choice between a radial metric size and a numeric bias-ply size depending on the result you want from the car.
The 4.5 Litre represents Daimler in a more formal and traditional luxury role, the kind of large British saloon where presence and ride character were as important as outright pace. Its tire fitment stands apart from the other 1966 Daimler models by using a 16-inch wheel, so correct identification matters before you move any further.
The SP 250 was Daimler’s fiberglass-bodied sports car, remembered for its compact proportions, distinctive styling, and more sporting mission than the marque’s saloons. It uses 15-inch fitments and gives owners a choice between a smaller radial metric size and a numeric bias-ply size, so the decision often reflects whether the car is being prepared for touring, showing, or a more original-style presentation.
Forty-two products are available across five tire sizes for 1966 Daimler vehicles. 185R15 includes 7 radial choices from Coker Classic and Michelin in redline, narrow whitewall, and blackwall form; 640-15 has 8 bias-ply choices from BFGoodrich and Firestone in wide and narrow whitewall styles; 700-16 has 10 bias-ply choices from Lester, Avon, BFGoodrich, and Firestone in blackwall and wide whitewall; 165R15 has 14 radial choices from Coker Classic, American Classic, Firestone, and BFGoodrich in wide whitewall, narrow whitewall, and blackwall; 590-15 has 3 bias-ply choices from BFGoodrich and Avon in blackwall and wide whitewall. Confirm your model, size, and construction preference before selecting, since speed ratings vary within some sizes.
These answers sort out the model-by-model size split for 1966 Daimler, the choice between bias-ply and radial construction where both exist, and practical details such as sidewall style, rim width, road use, and collector-car storage.
Size Basics & Fitment
What tire sizes fit 1966 Daimler vehicles?
1966 Daimler vehicles use five different tire sizes across three models. The 2.5 Litre uses 185R15 or 640-15, the 4.5 Litre uses 700-16, and the SP 250 uses 165R15 or 590-15. Rim diameter is split between 15-inch and 16-inch fitments, so these sizes are not interchangeable across the full 1966 Daimler range. Where rim-width guidance is available, 185R15 fits 4.5- to 6.5-inch wheels, 640-15 fits 4.0- to 5.0-inch wheels, 700-16 fits 4.5- to 5.5-inch wheels, 165R15 fits 4.5- to 6.0-inch wheels, and 590-15 fits 4.0- to 4.5-inch wheels.
The practical takeaway is that year and make alone are not enough for ordering tires on a 1966 Daimler. Start by identifying the exact model, then confirm whether your car is staying with a 15-inch or 16-inch wheel, and only after that compare bias-ply versus radial options where both are available. That sequence prevents the most common mistake, which is choosing a plausible-looking size that belongs to a different Daimler model from the same year.
What does 185R15 mean on a 1966 Daimler tire?
On a 1966 Daimler, 185R15 is a radial metric size. The 185 is the nominal section width in millimeters, the R identifies radial construction, and the 15 is the wheel diameter in inches. Because no aspect ratio is printed in the basic size code, it is conventionally treated as an 80-series radial. On 1966 Daimler applications, this size belongs to the 2.5 Litre rather than the full model range.
That matters because 185R15 is not simply a modern way of writing a 15-inch tire; it points to a specific radial fitment with its own wheel-width range and sidewall options. If your 2.5 Litre is already on 15-inch wheels and you want a radial format that suits regular road use, this is the size to investigate first. It is still wise to verify the actual wheel width before making a final choice, especially on cars that may have changed wheels during restoration.
Do all 1966 Daimler models use the same tire size?
No, 1966 Daimler models do not share one universal tire size. The 2.5 Litre uses 185R15 or 640-15, the SP 250 uses 165R15 or 590-15, and the 4.5 Litre uses 700-16. That means there is both a model split and a rim-diameter split within the year, with the 4.5 Litre standing apart on a 16-inch fitment while the other two models use 15-inch tires.
For a buyer, that means the model name matters every bit as much as the year and make. A tire that is correct for a 2.5 Litre may be wrong for an SP 250 even though both cars use 15-inch wheels, because the actual size and intended character differ. If you are comparing tires for a Daimler project that came to you without complete records, confirm the model first and then compare the correct sizes rather than assuming all 1966 Daimlers align.
Buying the Right Tire
Should I choose the 185R15 or the 640-15 for my 1966 Daimler?
For a 1966 Daimler 2.5 Litre, the choice between 185R15 and 640-15 is mainly a construction and character decision. The 185R15 is a radial metric size, while the 640-15 is a numeric bias-ply size, and both mount on 15-inch wheels. The radial choices in 185R15 also bring a broader spread of sidewall appearances, including redline, narrow whitewall, and blackwall, while 640-15 stays rooted in traditional bias-ply whitewall presentation.
Owners pursuing a more original mid-1960s look often lean toward 640-15, especially on a restoration where period-correct visual character matters. Owners who plan to drive their 2.5 Litre more regularly often begin with 185R15 because it keeps the 15-inch fitment while moving to radial construction. The key is to match the tire to the car’s intended role instead of treating the two sizes as simple substitutes for one another.
What sidewall styles are available for 1966 Daimler tires?
1966 Daimler tires are available in several sidewall styles depending on size. The 185R15 size comes in redline, narrow whitewall, and blackwall; 640-15 comes in wide whitewall and narrow whitewall; 700-16 comes in blackwall and wide whitewall; 165R15 comes in wide whitewall, narrow whitewall, and blackwall; and 590-15 comes in blackwall and wide whitewall. That gives the 1966 Daimler range a wide visual spread, from understated sporting blackwalls to more formal period-style whitewalls.
Choosing the right sidewall is often about the personality of the specific Daimler model as much as the size itself. A saloon restoration may call for a more traditional whitewall treatment, while a sports car owner may prefer a blackwall or a subtler whitewall depending on the era look being targeted. If authenticity matters for judging or marque correctness, compare your tire choice to period photos and club guidance for your exact model rather than assuming one sidewall style suits every 1966 Daimler.
What brands make tires for 1966 Daimler vehicles?
Several brands cover 1966 Daimler fitments. The 185R15 size is available from Coker Classic and Michelin, 640-15 from BFGoodrich and Firestone, 700-16 from Lester, Avon, BFGoodrich, and Firestone, 165R15 from Coker Classic, American Classic, Firestone, and BFGoodrich, and 590-15 from BFGoodrich and Avon. That gives 1966 Daimler owners access to both heritage-style American brands and long-established European names depending on the size they need.
Brand choice usually comes after the more important decisions of model identification, size confirmation, and construction type. Once those are settled, the brand comparison becomes a matter of sidewall appearance, series character, and in some cases speed-rating differences within the same size. It is a good idea to narrow the correct size first, because the available brand mix changes quite a bit between the 2.5 Litre, 4.5 Litre, and SP 250.
Fitting & Setup
What rim width do 1966 Daimler tires require?
Rim-width requirements on 1966 Daimler tires depend on the exact size. The 185R15 size fits rims from 4.5 to 6.5 inches wide depending on the tire, 640-15 fits 4.0 to 5.0 inches, 700-16 fits 4.5 to 5.5 inches, 165R15 fits 4.5 to 6.0 inches, and 590-15 fits 4.0 to 4.5 inches. Those ranges are broad enough that two tires with the same nominal size can still prefer slightly different wheel widths.
That is why wheel measurement matters before making a final selection, especially on a collector car that may no longer wear its factory wheels. If your Daimler has been restored, modified, or inherited with little history, measure the actual wheel width rather than relying on memory or appearance. Staying within the tire’s approved range helps preserve intended shape, tread behavior, and clearances without forcing a tire onto a wheel that is too narrow or too wide.
Do 1966 Daimler tires require inner tubes?
Tube use on 1966 Daimler tires is not the same across every size. The 185R15 radial options shown here are tubeless, marked TL on the Michelin examples, while the other sizes do not carry a universal tube marking across every product. With bias-ply fitments such as 640-15, 700-16, and 590-15, and even with some vintage-style 15-inch applications, tube choice should be treated as a tire-and-wheel decision rather than assumed from size alone.
The important next step is to match the tire not only to the model and wheel diameter, but also to the wheel construction and the exact sidewall marking on the product you choose. Original-style wheels, wheel condition, and rim design can all influence whether tube use is appropriate. Confirm that point before mounting, particularly on older restored wheels where the safest setup may differ from what a modern wheel would allow.
Can the original 1966 Daimler wheels be used with all tire sizes?
Original 1966 Daimler wheels cannot be treated as universal across all models because the range uses both 15-inch and 16-inch tire sizes. The 2.5 Litre and SP 250 use 15-inch fitments, while the 4.5 Litre uses 700-16 on a 16-inch wheel. Even among the 15-inch tires, rim-width ranges differ enough that the wheel on one model is not automatically ideal for another size.
A wheel that is correct for one 1966 Daimler may therefore be the wrong diameter or the wrong width for another. If you are working from loose parts, a mixed collection of wheels, or a car that has changed hands several times, confirm wheel diameter first and then compare actual width against the approved range for the tire you want. That is especially important when switching between radial and bias-ply options on the same model.
Maintenance, Storage & Longevity
How should I store a 1966 Daimler when the tires are fitted?
A 1966 Daimler should be stored in a cool, dry, dark space away from direct sunlight, electric motors, battery chargers, welders, and other ozone-producing equipment that accelerates rubber aging. Keep the tires properly inflated, move the car periodically if possible, and avoid long-term contact with standing moisture or oil-contaminated surfaces. Bias-ply tires such as 640-15, 700-16, and 590-15 are more prone to flat-spotting during static storage than radial sizes like 185R15 and 165R15.
That difference matters on a collector Daimler that may sit for weeks at a time between drives. If the car will be parked for an extended period, some owners reduce stress on the carcass with cradles or stands while still following safe support practices for the vehicle itself. Good storage habits preserve sidewalls, reduce vibration on the next outing, and help keep a rarely driven classic from aging its tires out before the tread is ever worn down.
How long do tires on a 1966 Daimler typically last?
On a 1966 Daimler, tire life is usually governed more by age than by mileage. A collector vehicle often accumulates limited use, so the more important benchmark is regular age-based evaluation beginning around five to seven years, with serious replacement consideration as tires approach ten years from the DOT manufacturing date. That applies whether the car is on radial 185R15 or 165R15 tires or on bias-ply 640-15, 700-16, or 590-15 tires.
A tire that still has deep tread can still be too old for confident road use if the rubber has hardened, cracked, or lost resilience. Check the date code, inspect the sidewalls and tread base carefully, and factor in how the car has been stored. Age matters even more on low-mileage classics because infrequent use can hide deterioration until the car finally goes out on a longer drive.
How often should tires on a 1966 Daimler be inspected?
Tires on a 1966 Daimler should be inspected before every drive, and more thoroughly before any extended outing or event. Look for sidewall cracking, cuts, bulges, embedded debris, uneven wear, and any sign that the tire is losing pressure between uses. If your car runs an older-style fitment that uses or may use tubes, include valve stems and air retention on your inspection checklist because those parts can age along with the tire itself.
That routine is especially important on a vintage Daimler because long periods of inactivity can be harder on tires than steady use. A brief walk-around catches issues while the car is still in the garage instead of on the roadside. Frequent inspections also help you spot whether a change in handling or ride is coming from the tire itself, from wheel condition, or from another chassis issue that deserves attention before the next drive.
Restoration & Authenticity
What tires were originally fitted to the 1966 Daimler 2.5 Litre?
For a 1966 Daimler 2.5 Litre, the period-correct starting point is bias-ply construction, reflected here by the 640-15 size. Radial 185R15 options are also available for the model, but a mid-1960s British saloon would have been born in the era when bias-ply fitments were still standard equipment on many cars. The exact sidewall treatment and market-specific presentation could vary, so final originality decisions should be tied to your car’s restoration goal rather than to one blanket answer.
That means a concours-minded owner will usually begin with 640-15 and then refine the choice by sidewall look, while an owner building a road car may still decide the radial path better suits the way the car will be used. If originality matters down to export-market detail, period literature and marque-club advice are the best places to verify the exact finish that belongs on your individual car.
Does correct tire fitment matter for showing a 1966 Daimler?
Correct tire fitment matters a great deal when showing a 1966 Daimler, especially at events that judge authenticity rather than general presentation. Judges and knowledgeable enthusiasts often notice whether the size matches the model, whether the construction type suits the era, and whether the sidewall treatment looks appropriate for the car’s class and period. A radial on a car judged for strict originality, or a sidewall style that clashes with the intended restoration theme, can stand out immediately.
That does not mean every show car must wear the same type of tire, because standards vary by event and by how the car is being presented. A touring-oriented restoration may prioritize road manners, while a factory-authentic restoration may prioritize period appearance. Before finalizing a set, compare your plans with the judging standards of the event you care about and with advice from Daimler specialists who know model-specific expectations.
What tires were originally fitted to the 1966 Daimler SP 250?
For a 1966 Daimler SP 250, the historically faithful starting point is the 590-15 bias-ply size rather than the later-feeling 165R15 radial alternative. The SP 250 is a sports car, but it still comes from a period when bias-ply construction remained the normal original-equipment choice. Blackwall and whitewall treatments both exist in 590-15, so authenticity is not only about size and construction but also about choosing a sidewall appearance that matches the way your particular car is being restored.
Owners who want the car to read correctly as a 1960s Daimler sports car at first glance usually start with 590-15 and then fine-tune from there. Owners who intend to drive the car more frequently may still prefer 165R15, but that is a use-based decision rather than a strict originality one. For market-specific or event-specific guidance, period photos and marque-club knowledge remain the best final check.
Safety & Road Use
Are 1966 Daimler tires safe for highway driving?
1966 Daimler tires can be suitable for highway use when the correct size is chosen, the tires are in sound condition, and the speed capability matches the way the car will be driven. Some sizes carry explicit speed ratings: 185R15 appears in H-rated form up to 130 mph and V-rated form up to 149 mph, 590-15 appears in H-rated form up to 130 mph, and 700-16 appears in at least one L-rated commercial-style form up to 75 mph. Other tires in these sizes do not always carry the same marked speed rating, so the exact product matters.
On a 1966 Daimler, the tire’s speed symbol is only part of the real-world equation. Brakes, suspension condition, steering, alignment, and the general limits of a vintage car can matter as much as the tire at normal highway speeds. Match the tire to the intended use, stay within the marked rating of the exact product, and treat long-distance or higher-speed touring as something the whole vehicle must be prepared for, not just the tire alone.
What inflation pressure should I use for 1966 Daimler tires?
Inflation pressure on 1966 Daimler tires should be set by the combination of the vehicle’s factory recommendation and the maximum load-and-pressure marking of the exact tire. Current examples include 185R15 at 1355 pounds at 35 psi, 640-15 at 1190 pounds at 32 psi or 970 pounds at 32 psi depending on the tire, 700-16 at 1800 pounds at 36 psi or 1900 pounds at 36 psi, 165R15 at 1168 pounds at 35 psi or 1170 pounds at 36 psi, and 590-15 at 1050 pounds at 32 psi. Those figures are not interchangeable from one size to another.
Use the owner’s manual or marque literature for the car’s intended operating pressure, then compare it with the tire maker’s sidewall information so you are not confusing a rated maximum with a day-to-day setting. Because 1966 Daimler fitments span different models, weights, and constructions, copying pressures from another Daimler owner can lead you astray. Keep a log of cold pressures and recheck them regularly, especially if the car is driven infrequently.
What should I check before taking a 1966 Daimler on a longer drive?
Before a longer drive in a 1966 Daimler, inspect all four tires and the spare for visible cracking, cuts, bulges, irregular wear, and correct cold inflation pressure. Make sure the tires are the correct size for the model, verify that valve stems are sound, and pay extra attention to air retention if the car uses an older-style fitment where tube service may be part of the setup. Also look over wheel condition and lug security as part of the tire check.
A longer outing is also the right time to think beyond the tires, because a vintage Daimler depends on the whole car being healthy. Brakes, cooling, steering, lights, and fluid levels all deserve attention before distance touring. From the tire standpoint, the goal is simple: leave only when the carcass condition, pressure, and age of each tire support the trip you are about to ask the car to complete.
